Pneumatic tire and method of making it



June 7, 1932. G. D MALLORY PNEUMATIC TIRE AND METHOD OF MAKING IT Filed May 31. 1930 m n m 3 Gerald D. Plallorq Patented June 7, 1932 UNITED STATES PATENT OFFICE GERALD D. MALLORY, OF AKRON, OHIO, ABSIGNOB TO THE GOODYEAR TIRE d; RUBBER COMPANY, OF AKRON, OHIO, A CORPORATION OF OHIO t PNEUMATIC TIRE AND METHOD OF MAKING IT Application filed May 31,

This invention relates to pneumatic tires and methods of making them, and it has particular relation to a pneumatic. tire having relatively small bead rings that are adapted B to be mounted directly upon hub portions of aircraft landin gear, or other vehicles.

One object of the invention is to provide a tire in which rubberized cord fabric is evenly distributed in such manner as to prevent premature failure of the tread portion of the tire.

Another object of the invention is to provide a method of distributing cords of tirebuilding fabric in such manner as to avoid failure of the tire at the tread, without increasing the thickness thereof.

For a better understanding of the invention, reference may now be had to the accompanying drawing, forming a part of this specification, of which Figure 1 is a side elevational View of a tire constructed according to the invention, parts thereof being omitted for the sake of clearness;

Figure 2 is a fragmentary, perspective and cross-sectional view, showing diagrammatically the principal features of the tire; and

Figure 3 is an elevation and cross-sectional view of a tire band mounted upon a cylindrical forming member, according to the invention.

In practising the invention, a pluralit of rubberized cord fabric plies 10, 11, 12 an 13, having their edge portions lapped and secured about bead rings 14, are mounted upon a substantially cylindrical tire-building drum 16 to form a unitary'tire band 17. A collapsible segmental portion 18 removably mounted upon a supporting portion 19 of the drum, directly receives the plies and it can be slipped from the cylindrical supporting portion. Thereafter, the band 17 is removed by collapsing the segmental portion 18.

After the first two plies 10 and 11 have been applied to the drum in such manner that their cords 22 and 23, respectively, are disposed dia onally of the band in opposite directions, a ditional relatively narrow lies 25 and 26 are superposed thereon. Cor s 27 of the inner narrower ply 25 are arranged substantially parallel to the cords 23 of the 1930. serial No. 457,773.

ply 11, and cords 28 of the ply '26 are arran ed transversely of the cords 27 Then the p ies 12 and 13 are applied in such manner that cords 30of the ply 12 are disposed substantially parallel to the cords 28 of the outer narrower ply 26, while the cords 32 of the outer ply 13 are arranged transversely of the cord 30. In order to insure more or less strengthening of the tire toward the outer periphery or tread thereof, the narrower plies 25 and 26 are selected of different widths, thus providing a stepped relation.

In shaping the cylindrical band 17, the center or tread portion is moved radially outwardly while the bead rin 14 are moved toward each other, and the nal shaping of the band into a tire 33 is effected by vulcanizing or curing it in a mold having a cross-sectional shape corresponding to that shown by Figure 2. During this final shaping, heat and ressure applied to the tire forces the cor s 27 of the ply 25 into interfitting relation between the cords 23 of the ply 11. As soon-as the rubber in the tire becomes soft during the vulcanizing operation, the cords 27 are only slightly resisted in their movement toward a position between the cords 23, where they are disposed in substantially perfect parallel relati on. Likewise, the cords 28 are forced into interfitting relation between the cords 30 of the ply 12. Thus the plies 11" and 25 are merged into a single ply having a. large number of cords at the tread portion of the tire, and a relatively small number at the head portion thereof. The same conditions are true with regard to the plies 12 and 26.

After the tire has been shaped in the manner described, it will be apparent that the cords at the bead portion of the tire are not crowded more than they were in the original band 17.

However, the tread portions of the plies 11 and 12 are greatly increased in diameter and accordingly, the cords of each ply are spaced considerably from each other, thereby roviding suflieient space to receive the cor s 27 and 28 therebctween. By practising this invention in the art of building tires of the type described,substantially the same type of drum or forming core can be employed as 2 1,sea,4ea

that em loyed in building ordinary so-called flat-bui t tires, with the exception that it is. much longer axially. At the same time, excessive spacing of the cords is compensated 5 by the introduction of additional interfittin cords which are not crowded about the bea of the tire.

Although I have described but the preferred forms which the invention may as- 10 same, and have described those forms in detail, it will be apparent to those skilled in the art that the invention is not so limited but that various modifications may be made therein without de artin from the spirit of I the invention or unit e scope of the ap nded claims.

What I claim is:

1. A pneumatic tire com rising a lurallig of lies of rubberized cor fabric, to co 50 at t e tread portion of the tire in one of the plies being materiall more numerous than the cords adjacent t e bead portion of the tire in the same ply.

2. A pneumatic tire comprising a series of as rubberized cords extendin substantially diagonally from one side of e tire to the other, and shorter rubberized cords arran d between the cords of the first-mentione series.

8. A pneumatic tire comprising a lurallitg M of plies of rubberized cor fabric, t e co of each of a plurality of the plies being arranged in two series, the first series extending from one bead of the tire to the other, and the cords of the second series bei s aced sub- I stantially equidistantly 'from 0 ads, the

cords of the second series in each of a plurality of the lies being difl'erent in length from the co s of the second series in an adjacent ply.

0 4. A method of making tires which comrises superposmg plies of rubberized cord abric in substantially cylindrical form,

shaping the plies into toroidal form, and interfitting cords of two adjacent plies to Al form a single ply during the shaping operation.

5. A method of making tires which comprises shapin a ply of cord fabric in substantially indrical form, super ing 80 thereon a re atively narrower pl 0 cord fabric with its cords running in an antially parallel relation to an ad]acent wider ply, and subsequently arranging the cords of the narrower ply between 0 cords of the wider It ply die form a single ply including all of the Inwitness whereof, I have hereunto signed my name.

Si ed at Akron in the county of Summit -00 and tate of Ohio, S. A., this 28th day of May, 1930. 4

GERALD D. MALLORY. 

